Currently, in a wireless communications network such as a Universal Mobile Telecommunications System (UMTS) or Long Term Evolution (LTE), a terminal device can be connected only to one cell, and the cell is referred to as a serving cell of the UE. One base station may usually have one or more cells. Each cell has a specific coverage area, and the coverage area is relatively fixed. If the UE leaves a current cell and enters another cell in a moving process, the terminal device (e.g., the UE) is handed over to the another cell based on an existing mobility management technology.
For example, as shown in FIG. 1, an existing handover procedure usually includes the following steps.
Step 101: A terminal device starts neighboring cell measurement, and reports a neighboring cell measurement result to a serving base station using a measurement report.
Step 102: The serving base station determines a suitable target cell based on the neighboring cell measurement result, and sends a handover request message to a target base station corresponding to the target cell.
Step 103: After determining, based on a resource status of the cell, to accept the UE, the target base station sends a handover acknowledgment message to the serving base station.
Step 104: The serving base station sends a handover command to the terminal device.
Step 105: The terminal device is handed over to the target cell based on the handover command, and returns a handover acknowledgment message to the target base station.
It is known to all that the foregoing handover procedure may cause transmission interruption of user plane data of the terminal device and an increase of a large amount of handover signaling.
In addition, as cell deployment density and complexity sharply increase, it is correspondingly more difficult to predict inter-cell interference distribution. Therefore, a handover procedure failure due to a radio link failure caused by interference also increases substantially, and consequently a service of the UE is interrupted due to a handover failure, and user experience is relatively poor.
Therefore, how to avoid, as much as possible, transmission interruption of user information and an increase of a large amount of handover signaling due to frequent inter-cell handover is a problem urgently to be resolved in the industry.